Oscillating centrifuge



T. WIRTH ET AL OSCILLATING CENTRIFUGE Feb. 3, 1959 Filed Oct. 29, 1957 2 Sheets-Sheet l I! m & T R n F|.||||-| 1. N We T Z g u n m mm w m 2 f my? MM N TKKWW W\ Y g B i mw d \w NW W xv M MN sm wv MN Feb. 3, 1959 T. WlRTH ET AL OSCILLATING CENTRIFUGE 2 SheetsSheet 2 Filed Oct. 29, 1957 INVENTORS, Thomas Wz'rfz BY KarF-Aezivz 1142662164 Kai! VVzzger United States OSCILLATIN G CENTRIFUGE Thomas Wirth, Dachau, Karl-Heinz Nebhuth, Darmstadt-Arheilgen, and Karl Wenger, Munich-Allach, Germany Application October 29, 1957, Serial No. 693,086

19 Claims. (Cl. 210-370) over the lip of the conical basket wall for discharge from the basket without damage to the granular structure of the dried material, whereas the mechanical discharging devices with which other centrifuges are equipped, tend to destroy the granular structure of the dried solid material.

In existing centrifuges of the kind wherein the basket is axially oscillated in order to effect the continuous discharge of dried solid material therefrom, the basket is elastically connected to the spindle of the centrifuge either by an elastic bottom in the basket or by springs which :are connected between a rigid bottom in the basket and the spindle, thereby freeing the basket for oscillation axially relative to the spindle, while the spindle is axially movable in a support which is, in turn, elastically connected to the frame of the centrifuge. In a centrifuge having the above arrangement, axial oscillations are directly imparted to the slidable spindle which forms a balancing mass elastically coupled to the basket to form an oscillating system having dual masses. With such a dual mass oscillating system, the masses of the basket and spindle, respectively, may oscillate either in the same or in opposite directions, and alternating forces are always transmitted from the support of the centrifuge to the frame or foundation thereof by Way of the elastic connection therebetween. These alternating forces will be relatively small when the masses of the basket and spindle, respectively, oscillate in opposite directions, however, since the oscillations are directly imparted only to the mass of the spindle, the masses of the basket and spindle will oscillate in opposite directions only within a narrow range of frequencies.

In other existing centrifuges of the kind wherein the dried solid material is discharged from the basket by effecting axial oscillation of the latter and employing a dual mass oscillating system, the frame of the centrifuge acts as the balancing mass and is elastically connected to the foundation so that, in such an arrangement, the momentum of the masses is also transmitted to the foundation by way of the elastic connection between the latter and the oscillating'mass of the centrifuge frame. The alternating forces resulting from the transmission of the momentum of the masses are, in turn, transmitted from the foundation of the floor of the building structure housing the centrifuge or to adjacent machinery, and frequently causes structural damage to the building or interference with the mechanical efiiciency, or even operativeness, of the centrifuge and of adjacent machines. Such transmission of the forces from the foundation to the ate-ntoscillation of the basket carries the dried solid material ICQ building structure and to adjacent machines may be overcome by providing a foundation for the centrifuge having as great a mass as possible, and by providing the foundation with an elastic support, for example, of cork or rubber, which tends to reduce the amplitude of the alternating stresses transmitted to the building structure. However, such foundations are costly and are not always practical, for example, in cases where the centrifuge is to be installed on the upper floors of a building. Furthermore, the vibrations of the centrifuge frame are transmitted to the drive motors of the centrifuge mounted on the frame thereof, and also to the transmission members, such as, belts, drive shafts and the like, thereby to increase the load on the motor bearings, the motor windings and the transmission members and to correspondingly reduce their useful life. In the described existing arrangement the bearings carrying the spindle are also subjected to high stresses by reason of the oscillation of the balancing mass, that is, the frame of the centrifuge, which does not rotate with the spindle, and whereon the bearings is thereby increased.

Accordingly, it is an object of the present invention to provide a centrifuge of the kind described above, and wherein the axial oscillations of the centrifuge basket for effecting the continuous discharge of the dried solid material are isolated fromthe foundation of the centrifuge and also from the drive motors, the transmission members and the bearings carrying the spindle.

In accordance with an aspect of this invention, the oscillations of the basket are isolated from the foundation, drive motors, transmission members and the bearings supporting the spindle by elastically connecting both the mass of the basket and the balancing mass to the frame of the centrifuge, but in opposite directions, so that the forces transmitted by the resulting dual-mass oscillating system to the frame of the centrifuge always act simultaneously upon the latter, but in opposite directions, so that oscillation of the centrifuge frame is essentially eliminated.

Further, in accordance with the invention, mutual cancellation of the forces exerted on the centrifuge frame by the oscillating basket and balancing mass, respectively, is ensured by providing an oscillation generator operatively connected'to the balancing mass and to the basket in order to produce synchronous, inverse or opposed oscillations of the basket and of the balancing mass at all frequencies.

A further feature of the invention resides in providing a drive assembly for rotating the spindle and the basket which does not participate in the oscillations of the basket and the balancing mass, so that such oscillations are isolated from the elements of the drive assembly, for example, drive motors, drive shafts, transmission belts and the like.

The above, and other objects, features and advantages of the invention, will be apparent in the following de tailed description of an illustrative embodiment thereof which is to be read in connection with the accompanying drawing-forming a part hereof, and wherein:

Fig. 1 is a longitudinal, sectional view of an oscillating centrifuge embodying the present invention, with auxiliary devices associated with the centrifuge being shown schematically;

Fig. 2 illustrates additional auxiliary devices; and

Fig. 3 is a diagrammatic representation of the operating principles of the centrifuge illustrated in Fig. 1.

Referring to the drawing in detail, and initially to Fig. 1 thereof, it will be seen that an oscillating centrifuge embodying the present invention and there generally identified by the-reference numeral 10 includes a centrifuge basket 11 having a frusto-conical, perforated side wall 12 and an end wall 13 closing the relatively small diameter end of the basket. The basket 11 is arranged with its 2,8 more central axis extending horizontally and'is mounted within a centrifuge frame or housing 14, as hereinafter described in detail, for rotation about its horizontal central axis and for oscillation or reciprocation in th'e an uish-urinating of rotation. A stationary feed pipe extends saws wardly into the frame or housing l i'aii d is then bent," as

shown, to extend axially into the-basket 11 through'the open, relatively largedi'ameter end of the-'latter andto terminate adjacent the end wall13f0r suppiyingmeslanof liquids and solid materials which are to 'beseparard to the centrifuge basket. The angle of inclination of the perforated side wall 12 of the centrifuge basket relative to the central axis of rotation of the latter is selectedQto be smaller'than the angle of repose of the'material which is to be centrifuged, so that such material will not spun taneously flow out'of the open, large diameter end of the basket 11, and will be'discharged throughthe open end of the basket only in'response to axial oscillation of the latter. Since the amplitude and frequency of the axial oscillations of basket 11 are adjustable, as hereinafter indicated in detaihthe dwell time of the solid material in the basket 11 prior to discharge'from the latter can be varied in order to regulate the operation of the centrifuge in connection with the properties of the solid material being separated.

In order to mount the basket 11 for rotation and axial oscillation within the frame or housing '14, the latter is provided with a partition 16 extending thereacross and centrally carrying a bearing 17 which rotatably supports one end of an open-ended, hollow shaft 18, and the latter is also rotatably supported, adjacent its opposite end, in a bearing'19 fixed in one end of a cylindrical casing 20 which is suitably secured in an end wall 21 of the frame or housing 14. A spindle 22 is rigidly secured, at one end, to the end wall 13 of basket 11 and extends axially from the latter through the hollow shaft 18. In order to coupleithe spindle 22 to the hollow shaft 18 for rotation with the latter, while permitting axial oscillation of the spindle relative to the shaft 18 which is held against axial displacement with respect to the housing 14, a pin or wedge 23 passes through a diametrical bore in the at 33a, -is bored and carries a diametrically extending cross-piece 33 extending outwardly through diametrically opposed pairs of registering, axially elongated slots 34 and in the hollow portion 22a of the spindle and in the hollow shaft 18, respectively, while the outer ends of the cross-piece 33 are secured within the balancing mass 31.

A relatively strong helical compression spring 36 extends around the hollow shaft 18 and abuts, at its opposite ends, against the sleeve 29 and the balancing mass 31, respectively,to act as an elastic-coupling between the balancing mass, which is connected by the cross-piece 33 to oscillate with the rod 32, and the sleeve 29 which is connected, by the pin 23, to oscillate with the spindle 22 and basket 11. Further, helical compression springs 37 and 3S acting as elastic spacers extend around the hollow shaft 18 and are axially interposed between the sleeve 29 and a collar 39 abutting against the partition 16, and between the 'rna'ssiilan'd a collar 44 abutting against the casing 20 secured in-the end'wall 21, respectively.

In order to effect synchronous oscillations of the basket 11 and balancing mass 31 in opposed directions at all frequencies, the'centrifugeltl embodying the presentinvolition includes acylinder 41 which isslidable within the cylindrical casing 20 and axially coupled to the end of the spindle '22 remote from the basketll, and a piston 42 which is slidable within the cylinder 41 and connected to the'end of the rod 32 remote from the cross-piece 33.

Thus, when fluid under pressure is admittcd to the cylinder that-the right hand side of the piston 42, as viewed in Fig. 1, the piston 42 as well as the balancing mass 31 will be' driventoward the left, while the cylinder 41, the

spindle 22 and the basket 11 will be driven toward the right. 'Conversely, when fluid under presusre is admitted spindle 22 and extends radially outward through'a pair of diametrically opposed, axially elongated slots 24'provided in the hollow shaft 18 intermediate the ends of the latter.

In order to effect rotation of the hollow shaft 18, and hence also rotation of the spindle 22 by way of the coupling provided between the shaft 18 and spindle 22 in the form of the pin 23 engaging in slots 24, a pulley 25 is suitably secured on the end of hollow shaft 18 remote from the basket 11 and is engaged by endless transmission belts 26 which also run around a pulley 27 secured on the shaft of a drive motor 28. Since the hollow shaft 18 is only rotatable and does not participate in the axial oscillations imparted to the spindle 22, as hereinafter described in detail, the bearings 17 and 19 supporting the shaft 13, the transmission consistingof the belts 26 and the pulleys 2S and 27 and the motor 28 are'all isolated from the effects of such oscillations and are'thereby protected against the increased we'arthat results from the transmission of the oscillations to such operating parts.

' A sleeve 29 is slidably'mounted upon the hollow shaft 18 and is provided with bores 30 receiving the opposite ends of the pin 23 so that the sleeve 29 is thereby coupled to the spindle 22 for axial oscillation with the latter with respect to the hollow shaft 18. p

A balancing mass, preferably in the form of an annular member 31 which is split along a diarhetric plane to provide two separable parts which can be secured together around the hollow shaft 18, is slidably mountedon'the shaft 18 between the sleeve 29 and the end wall 21 of housing 14. The spindle 22 is formed with ahollow portion 22a opening axially in the direction away from the basket 11 and slidably receiving and 32 which, at' its inner end within the hollow/portion 22a of the spindle,

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to' the cylinder 41 at the left hand side of the piston 42, asviewed'inFig. l, the balancing mass 31 is driven toward the right,while the basket 11 is driven toward the left.

In a modified construction according to our invention, the balancing mass 31 is replaced by a second basket analogous tobasket 11, in which case we provide within the spindle 22 instead of the rod 32 a rod that passes through the piston 42 and also through the end wall of the cylinder '41 remote from the'pulley 25. The second basket is secured, beyond said end wall of the cylinder 41, to the free end of the rod. With this construction, the second basket acts as a balancing mass since the two baskets synchronously oscillate in opposite directions at the same frequency with the same amplitude. The throughput of this double centrifuge having the balanced characteristics described above with reference to the embodiment illustrated in Fig. l is practically doubled.

According to a modification of the embodiment shown and described hereinbefore, the springs 36, 37 and 38 are replaced by pneumatic and hydraulic pressure'cylinders. For instance, 'in such modification a sleevelike piston is slidably mounted on the hollow shaft 18 and abuts atone end against the sleeve 29. The piston is guided in a cylinder, the annular'bottom of which abuts accordingly against the collar 39. Air enclosed in the cylinderspace is compressed whenhydraulic fluid is admitted to the piston 42 at the side of the rod 32, and when hydraulic fluid is admitted to the other side of the piston the air expands. This device constitutes an elastic intermediary member analogous to helical spring 37. The elasticity of this intermediate member can be increased by connecting to the air-filled cylinder space an expansion chamber, such as is customary with piston pumps. An air-holding expansion chamber is definitely required when the hydraulic fluid for the cylinder is a liquid and the necessary elasticity of the system must be obtained despite the incompressibility of the liquid.

It is also possible to place a cylinder and piston analo- 'gous to the cylinder 41 and piston 42, respectively, inside of the hollow shaft 18. In this case, the hollow shaft assumes the function of the casing 20, and'the hollow -portion ofthe spindle 22 am as the cylinder 41in which the piston slides. The external diameter of the piston corresponds to the internal diameter of the hollow spindle portion.

As shown in Figs. 1 and 2, a system for supplying fluid under pressure to the cylinder 41 alternately at the opposite sides of the piston 42 therein may include conduits 43 and 44 connected to the casing 20 and opening into annular grooves 45 and 46, respectively, formed in the inner surface of the cylindrical casing 20 at axially spaced apart locations and permanently communicating amen with radial openings 47 and 48, respectively, in the cylinder 41 adjacent the opposite ends of the latter. The illustrated system further includes a source of fluid 49, in the form of a tank or reservoir, a pump 50 having its inlet side connected, as by a pipe 51, to the source 49, a supply line 52 for fluid under pressure extending from the discharge or outlet side of the pump 50, a return line or pipe 53 emptying into the source 49, and a rotary distributing valve 54 driven by a variable speed motor 55 which is independent of the motor 28 for effecting rotation of the basket 11. The rotary distributing valve 54 is operative, when driven by the motor 55, to alternately connect or establish communication between the conduits 43 and 44 and the supply line 52 and return line 53.

As shown merely by way of example in Fig. 2, the rotary distributing valve 54 may include a cylindrical valve body 56 connected, as at 57, to the motor 55 for rotation by the latter within a housing 58. The valve body 56 selected for illustration has four axially spaced apart slot-shaped recesses 59, 60, 59a, and 60a, which extend approximately to the axis of the valve body and are arranged in pairs on opposite sides. Spacedly provided in the housing 58 are four axially extending pipes 61, 62, 61a and 62a, each of which comprises two oppo- 52 between the pump 50 and the adjustable throttling valve 64 in order to absorb any pressure shocks that may be imparted to the fluid under pressure during operation of the pump.

Referring to Fig. 3, wherein the operating conditions achieved with the above described oscillating centrifuge are diagrammatically represented, it will be apparent that the masses a and b of the basket 11 and the balancing mass 31, respectively, with the interposed helical spring 36 coupling together the two masses created a dual-mass oscillating system, which, when the masses oscillate in opposite directions, does not exert any momentum on the frame 14 by reason of the provision of the spacing springs 37 and 38 which space the oscillating system from the transverse walls 16 and 21 of the frame and always exert equal and opposite forces against the frame 14. Thus, the forces exerted by the springs 37 and 38 against the frame 14 cancel each other, and oscillations of the centrifuge are not transmitted to the foundation supporting the latter or to any surrounding structure or adjacent machines. Further, since the balancing mass 31 rotates with the basket 11, no vibrations are transmitted to the bearings 17 and 19 which rotatably support the hollow shaft 18 and the bearings are thereby protected against excessive Wear.

The fluid under pressure supplied to the cylinder 41 for generating the desired oscillations of the basket and sitely directed branches, as the branches 61' and 61" I of the pipe 61, and the branches 62' and 62" of the pipe 62. Altogether there are eight such branches, the end portions of which are bent toward the interior of the valve body and open at points along generating lines of the inner wall of the cylindrical housing 58. The width of the recesses 59, 60, 59a, and 60a is such that one branch of each of the two pipes 61 and 62, as 61' and 62',-open into one and the same recess, as 59. Thus, the valve body is adapted to effect communication between two pipes over one of their branches, as between 61 and 62 over 61 and 62. Actually, in any of the operating positions of the valve body, the latter establishes communication between two pairs of pipes, as between 61 and 62 and between 61a and 62a, that is also between each of the conduits 43 and 44 and one of the lines 52 and 53. In the position of the valve body, as illustrated, the supply line 52 is shown to communicate over pipes 614: and 6211 With the conduit 43, while the conduit 44 communicates over pipes 62 and 61 with the return line 53. With the valve body rotationally displaced by approximately one hundred and eighty degrees, the supply line 52 will communicate with the conduit 44 over the pipe 61a, using the opposite branch of the latter, and the pipe 62, using the branch 62", and the conduit 43 will communicate with the return line 53, using the opposite branches of pipes 62a and 61.

It will be apparent that the variable speed motor 55, in changing the rotational speed of the valve body 56, will correspondingly vary the frequency at which the conduits 43 and 44 are alternately communicated with the supply line 52 and the return line 53, thereby to correspondingly vary the frequency of the oscillations imparted to the basket 11 and the balancing mass 31.

In order to permit adjustment of the amplitude of the oscillations imparted to the basket 11 and the balancing mass 31, an adjustable throttling valve 64 may be interposed in the supply line 52. Further, a pressure accumulator 65 may also be interposed in the supply line balancing mass may be either a gas or a liquid, and such fluid under pressure may be derived from a source of pressurized fluid which primarily serves other purposes, thereby to avoid the necessity for providing an individual source 49 and pump 50 for each centrifuge.

Although it is desirable to have the fluid under pressure supplied to the cylinder 41 alternately at the opposite sides of the piston 42, as described above, it is possible to eliminate one of the conduits 43 or 44 and to employ the remaining conduit for alternately connecting the related space in the cylinder 41 to the supply line 52 and the return line 53, respectively. Our oscillating centrifuge will operate satisfactorily even when the dual-mass oscillating system consisting of the mass of the basket 11 and the balancing mass 31, in cooperation with the helical springs 36, 37, 38 as elastic links, is excited in one direction only in the rhythm of its resonant frequency, whereby free oscillation of the masses is generated. In this modification, the recesses 59a and 60a of the valve body 56 of the rotary valve 54 (see Fig. 2) may be omitted, so that the supply line 52 and the return line 53 and conduit 44 will register in the area of the recesses 59 and 60. The piston 42 and the cylinder 41 will be driven in opposite axial directions upon the admission of fluid under pressure to the cylinder at one side of the piston.

In place of the axially movable cylinder 41, it is possible to substitute two fixed cylinders having pistons slidable therein and connected to the basket 11 and the balancing mass 31, respectively, while the supplying of fluid under pressure to such fixed cylinders is controlled. in order to provide for the desired oscillation of the basket, and balancing mass in opposite directions.

Furthermore, the single rotary valve 54 described above and employed for controlling the connection of the conduits 43 and 44 to the lines 52 and 53 may be obviously replaced by cam-controlled valves or by electrically or hydraulically-controled valves. It is also apparent that the rotatabe body 56 of distributing valve 54 may be driven by a variable speed transmission from the motor 28, rather than by a separate variable speed motor 55, as illustrated in the drawing.

In the case of cam-controlled valves instead of the rotary distributing valve 54, a spring-loaded disc valve similar to those used in internal combustion engines with a stem sliding by means of a cam follower on eccentric discs is arranged between each pair of coordinated ends of the pipes 61, 62, 61a and 62a. The eccentric discs are mounted on the shaft 57 driven by the motor 55. There are two pairs of such eccentric discs, but the two pairs are angularly displaced with respect to eachother by 180 so that when one pair of thervalves is lifted the supply line 52 is connected with the conduit 43, whilethe conduit 44 is connected with the return line 53. The connections are reversed when the other pair of valves is lifted. Thus, the same effect :is insured as with the rotary valve 54.

Although a single illustrativeembodimentof the invention has been described herein .with referenceto the accompanying drawings, and several modifications of-the illustrated arrangement have additionally been described, it is to be noted that the invention-is. not limited to the precise embodiments illustratedand descfibed, and. that many other changes and other modifications .may'be effected without departing from the. scope or spirit of the invention, except as defined in theappended'claims.

What is claimed is:

1. An oscillating centrifuge 'for eifectingithe continuous discharge of dried solid materials and comprising a frame, a basket mounted in said frame for rotation and for oscillation along the axis of rotation of the basket, a balancing mass mounted for oscillation along said axis of rotation and being elastically coupled with said basket to form, with the latter, a dual-mass oscillating system, drive means operatingin opposed axial directions on said basket and balancing mass, respectively, and elastic means coupling said basket and said balancing mass, respectively, to said frame in opposed-directions so that forces transmitted from said dual-mass oscillating system to said frame act simultaneously in opposite directions to practically eliminate the oscillation of said frame.

2. An oscillating centrifuge as in claim 1; wherein said drive means includes a single generating device for pro ducing oscillations of both-said basket and said balancing mass.

3. An oscillating centrifuge as in claim '2; wherein said drive means further includes coupling means between ssiidgeneratihg device and said basket and balancing mass, respectively, operative to cause said basket and balancing mass to oscillate synchronously in opposite directions at all operating frequencies.

4. An oscillating centrifuge as in claim 3; wherein said generating device is fluid pressure operated; and said drive means further includes means for supplying an operating fluid to said generating device at repeatedly varying pressures, and adjustable control :means effective to vary the frequency of the variation of pressure of the operating fluid.

5. An oscillating centrifuge asin claim 3; wherein said generating device includes a cylinder slidably mounted in said frame to move axially relative to the latter in the direction of said axis of rotation ofthe basket, and a piston axially movable within said cylinder, said coupling means connecting said basket to said cylinder and said balancing mass to said piston; and further comprising means for supplying fluid under pressure to said cylinder alternately at the opposite sides of said piston so that, in response to the admittance of fluid under pressure to said cylinder, said cylinder andpiston, and hence said basket and balancing mass, respectively, are displaced in opposite directions.

6. An oscillating centrifuge as in claim 5; wherein said means for supplying fluid under pressure includes conduits opening into the opposite ends of said cylinder, a source of fluid, pump means having an inlet receiving fluid from said source and a discharge for fluid under pressure, a fluid under pressure supply line extending from said discharge of the pump means, a return line extending back to said source, valve means connected to said conduits and'to said supply and return lines and operative, upon actuation, to alternately communicate said supply and return lines with said conduits, and independent, variable speed motor means connected to said valve-means for driving the latter at an adjustable speed, thereby to vary the frequency of oscillation of said basket and balancing mass.

7. An oscillating centrifuge as in claim 6; wherein said'means for supplying fluid under pressure further includes pressure accumulating means interposed in said supply line and operative to absorb pressure shocks during operation of said pump means.

8. An oscillating centrifuge as in claim 6; wherein said means for supplying fluid under pressure further includes an adjustable throttling valve interposed in said supply line and operative to control the flow of fluid under pressure through said supply line and, hence, to control the amplitude of the oppositely directed oscillations imparted to said basket and balancing mass.

9. An oscillating centrifuge as in claim 5; further compromising a hollow, open-ended shaft, bearing means rotatably mounting said hollow shaft in said frame coaxial with said axis for rotation of said basket, a spindle extending axially from said. basket and slidably received in said hollow. shaft, .means constraining said spindle to rotate with said hollow shaft while permitting axial oscillation of said spindle relative to said hollow shaft, said balancing mass being slidably mounted on said h0l low shaft, means constraining said balancing mass to rotate with said hollow shaft, rotational drive means, and transmission means connected between said rotational drive-means and said hollow shaft to rotate the latter and thereby to effect simultaneous rotation of said basket with said spindle and of said'balancing mass.

10. An oscillating centrifuge as in claim 9; wherein said spindle is directly connected to said cylinder and thereby forms said-coupling means between said cylinder and said basket.

11. An oscillating centrifuge as in claim 10; wherein said spindle has a hollow portion opening axially in the direction-toward said cylinder and said hollow shaft and said hollowportion of the spindle have registering axially elongated slots; and wherein said coupling means between said piston and said balancing mass includes a rod connected to said piston and extending axially out of said cylinder into said hollow portion of the spindle, and a cross-piece on said rod projecting radially through said registering slots and secured, at its ends, to said balancingrn'ass to transmit the axial displacements of said rod with the piston to said balancing mass and to define said means constraining said balancing mass to rotate with said hollow shaft.

12. An oscillating centrifuge as in claim 10; wherein said hollow shaft has axially elongated slots therein, and said means constraining said spindle to rotate with said hollow shaft includes a pin extending diametrically through said spindle and having its opposite end portions slidably received in said elongated slots.

13. An oscillating centrifuge as in claim 12; further comprising a sleeve slidable on said hollow shaft and connected to said pin to move axially with said spindle relative to said hollow shaft, and elastic intermediary means on said hollow shaft between said sleeve and said balancing mass to provide the elastic coupling between the latter and said basket.

14. An oscillating centrifuge as in claim 13; wherein said intermediary elastic means includes a helical compression spring extending around said hollow shaft.

15. An oscillating centrifuge as in claim 13; wherein said intermediary elastic means includes an axially compressible cylinder assembly containing fluid to yieldably resist axial compression thereof.

16. An oscillating centrifuge as in claim 13; wherein said frame has spaced apart laterally extending wall portions carrying said bearing means mounting the hollow shaft, with said sleeve and balancing mass being both disposed between said wall portions; and wherein additionalelastic means includes an elastic element interposed between said sleeve and the adjacent wall portion and an elastic element interposed between said balancing mass and other of said wall portions.

17. An oscillating centrifuge as in claim 14; wherein each of said elastic elements includes a helical compression spring extending around said hollow shaft.

18. An oscillating centrifuge as in claim 14; wherein each of said elastic elements includes an axially compressible cylinder assembly containing fluid to yieldably resist axial compression thereof.

10 19. An oscillating centrifuge as in claim 3; wherein said balancing mass is .in the form of a second basket so that, in response to the synchronous oscillation of said second basket and the first mentioned basket in op- 5 posite directions, dried solid materials are simultaneously and continuously discharged from both baskets.

No references cited. 

